Pressure actuated spring biased latch

ABSTRACT

The subject invention provides a latch mechanism particularly suitable for snap-lock attachment of a structure holding the latch to a structure having mating recesses. Generally, the invention relates to spring-biased, cam-operated latches and more particularly to a positive-locking latch device in which a circular band spring biases locking pins into retaining holes in a structure to which the latch is being attached. The latch is released by rotating a cam actuator which contacts the locking pins and withdraws them from the retaining holes.

United States Patent 1 1 Polk, Jr. 1 Jan. 16, 1973 54] PRESSURE ACTUATED SPRING 784,446 3 1905 Taylor ..292/37 BIASED LAT H 2,535,275 12 1950 Dixon ..292 37 x 2,905,943 9/1959 T h tt ..292 37 lnvemo Albert Bammore, 1,873,485 8/1932 Rgsv e ..292i37 [731 Assign: fgf g fi 5%: z g g z? 3: FOREIGN PATENTS QR APPLICATIONS Navy 2,465 0/1872 Great Britain ..292/37 [22] Filed: 1971 Primary ExaminerRobert L. Wolfe [21] Appl. No.: 173,445 Att0rneyJoseph A. Cooke et al.

Related US. Application Data [62] Division 889306 1969' The subject invention provides a latch mechanism particularly suitable for snap-lock attachment of a' structure holding the latch to a structure having mating (g llllllllllllll Q ?)AZ recesses. Generally, the invention relates to spring- 58 d 7 biased, cam-operated latches and more particularly to 1 le Q can 56 a positive-locking latch device in which a circular band spring biases locking pins into retaining holes in [56] p R f rences Cited a structure to which the latch is being attached. The

e e latch is released by rotating a cam actuator which con- UNITED STATES PATENTS tacts the lllolcking pins and withdraws them from the retamm 0 es. 1,901,613 3/1933 Smith ..70/259 g 3 Claims, 3 Drawing Figures PATENTEDJAH 16 I975 SHEET 2 BF 2 INVENTOR. ALBERT S. POLK JR PRESSURE ACTUATED SPRING BIASED LATCH CROSS-REFERENCE TO RELATED APPLICATIONS This application is a division of U. S. Pat. application Ser. No. 889,206, now U.S. Pat. No. 3,648,953 entitled, Fin Mount Latch.

BACKGROUND AND BRIEF SUMMARY OF THE INVENTION Space restrictions imposed on various augmented thrust missile designs have necessitated external engine geometries which prevent the use-of normal control surface attachment mechanisms. The present invention provides simple, effective means for attaching control surface/actuator packages, with control surfaces thereon, to a missile having externally mounted en gines. A saddle-type mounting is utilized which straddles each external engine. That is, a control box for each control surface forms a portion of the saddle mounting, said mounting including legs which straddle portions of the engine and are attached to fairings or shrouds along the missile by double-acting, positivelocking latches.

Use of the present invention allows rapid and facile installation of a control surface package on a missile by one person with the use of but a simple spanner wrench.

The latch disclosed herein finds utility in any number of applications. Such a simple, easily operated, yet effective latching device can readily be used with success as a car trunk latch, a tool cabinet latch, or a door lock.

It is therefore an object of the present invention to provide a latch for mounting control surfaces and related actuating devices on a missile utilizing external engines.

It is also an object of the invention to provide a positive-locking latch capable of providing rapid attachrnent of a stabilizing surface package to a missile body.

A further object of the invention is to provide simple, effective latching means for attachment and detachment of a control package to and from a missile and which is readily operable by one person without special equipment.

A still further object of the invention is to provide easily operable latching means which is also suitable for general use as a lock, catch, or stay.

Further objects and attendant advantages of the invention will become more readily apparent in the light of the following description of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged detail axial section of the latch of the present invention;

FIG. 2 is a plan view of the latch, shown in partial section and with the latch pins extended; and

FIG. 3 is a view similar to FIG. 2 but showing the latch pins retracted, a portion of the missile body being shown in broken lines.

DESCRIPTION OF THE PREFERRED EMBODIMENT The structure and operation of the latch shown generally at 10, may be best understood by reference to FIGS. 1 and 3, wherein said latch is seen to be comprised of mating discs 12a and 12b, two opposed latch pins 14, and a spring 16. The latch 10 is seen to be encased in supporting structure 18 which constitutes the structural element that is to be mounted or joined to a fixed structure, 19, shown in broken lines, by said latch.

The mating discs 12a and 12b cooperate to form a housing 20 and each have flat outer surfaces and elliptical recesses in their inner surfaces. Since the discs 12a and 12b are virtually identical, a detailed description of one of them will suffice. Accordingly, as best seen in FIGS. 1 and 2, a recess 22 in the disc 12a is bonded by a flange 24 which has a circular outer rim 26 and an elliptical inner wall 28. A hub 30 is formed on the center of the disc 12a and cooperates with a similar hub 32 on the disc 12b, screws 34 being employed for retaining the discs in cooperating relation. When joined together by the screws 34, the discs 12a and 12b provide an enclosed elliptical cavity 36, having an annular slot 38 The spring 16 is disposed within the enclosed elliptical cavity 36, and is of a diameter slightly smaller than the minor axis of said cavity 36.

The latch pins 14 are formed with spaced annular flanges 40 which impinge on the inner surfaces of cylindrical bores 42 formed in the structure 18, and with rounded outer ends 44 which readily fit into retaining holes 46 formed in fixed structure 19, as shown in FIG. 3. Corresponding inner end portions 50 of the pins 14 extend through the slot 38 into the elliptical cavity 36 and have enlarged heads 52 which slidably engage the elliptical wall 28. Corresponding inner end faces 54 of the heads 52 contact the spring 16. Normally, the spring 27 maintains a circular configuration and simply retains the pins 14 in engagement with the elliptical inner wall 28 of the cavity 36, when the outer ends 44 will be engaged in the holes 46 and the structure 18 connected to the fixed structure 19. Movement of the structure 18 into this position on the fixed structure brings pressure to bear on the rounded outer ends 44 of the latch pins 14 as they engage the confronting surface of the'structure 19, causing them to move toward each other along the bores 42 in said structure 18and to deform the circular spring 16, thus causing said spring to exert a force against said pins 14. As long as an external pressure greater than or equal to the force exerted by the spring in maintained, the pins 14 will remain inside the bores 42. On release of such external pressure, i.e., when the pins confront the retaining holes 46, said pins 14 will snap into positions with their rounded ends 44 extending into said holes.

Referring particularly to FIG. 2, the disc 12a of the housing 22 is seen to have circular sockets 56 disposed in its surface to receive the jaws of a spanner wrench (not shown) for detaching the structure 18 from the fixed structure 19, the flat outer surface of the disc 12a being flush with the exterior surface of the structure 18. More specifically, when the jaws of a spanner are inserted in the sockets 56 and the housing 22 is thereby rotated in either direction, the elliptical walls 28 of the cavity 36 cam the enlarged heads 52 of the pins 14 inwardly toward the center of the housing, thereby deforming the circular spring 16 into elliptical shape and biasing the latch pins 14 to positions where the rounded ends 44 are moved inside the bores 42 in the structure 18 and withdrawn from the retaining holes 46 in the fixed structure 19. In such a position, the structure 18 may be disengaged from the fixed structure 19. Removal of the tool allows the latch pins 14 to be moved back to their original positions by action of the spring 16.

The utility of this simple yet effective latching device causes it to be applicable to any number of uses requiring a positive locking latch. For example, the latch could be easily used as a car trunk latch operable either by closure of the trunk door or by operation with a standard key.

I claim:

1. A latch comprising, in combination with a surface having a retaining hole and an element for connection to said surface,

a latch pin on the element and having one end normally engagable in the retaining hole for connecting said element to said surface,

said latch pin having a head, a housing on the element and rotatable in said element and having a cam surface to move the head for withdrawing the pin from the retaining hole, whereby said element may be removed from the surface, the housing comprising mating pairs of connected discs defining a cavity having an elliptical wall and an annular slot in the wall and communicating with the cavity, said slot receiving said pin with said head in the cavity and engaging the wall.

2. The latch recited in claim 1, including additionally a spring in the housing and engaging the head for urging the pin toward engagement in the retaining hole.

3. The latch recited in claim 2, wherein the cam surface comprises an elliptical wall and wherein the head of the latch pin engages the spring and the elliptical wall, whereby upon rotation of the housing said latch pin by cam action of the wall on the head will be withdrawn from the retaining hole. 

1. A latch comprising, in combination with a surface having a retaining hole and an element for connection to said surface, a latch pin on the element and having one end normally engagable in the retaining hole for connecting said element to said surface, said latch pin having a head, a housing on the element and rotatable in said element and having a cam surface to move the head for withdrawing the pin from the retaining hole, whereby said element may be removed from the surface, the housing comprising mating pairs of connected discs defining a cavity having an elliptical wall and an annular slot in the wall and communicating with the cavity, said slot receiving said pin with said head in the cavity and engaging the wall.
 2. The latch recited in claim 1, including additionally a spring in the housing and engaging the head for urging the pin toward engagement in the retaining hole.
 3. The latch recited in claim 2, wherein the cam surface comprises an elliptical wall and wherein the head of the latch pin engages the spring and the elliptical wall, whereby upon rotation of the housing said latch pin by cam action of the wall on the head will be withdrawn from the retaining hole. 